Newish Berlingo No-Go

[addo]

1.6 Diesel, job I inherited after someone launched into a car with dead blower relay (they didn't know how to fix this) and suddenly "him no go". It doesn't even crank now.

Lexia tells me there is a problem with the power supply relay latch, but swapping the underbonnet panel (BSM) with a known good one made no change; for giggles I proved the faulty van's panel also worked fine in the donor van.

Further, Lexia doesn't talk to the ECU at all. Not a squeak, which says to me it's not getting power.

Desperate for suggestions; I really want to get this sorted ASAP as I've booked a week away from Wednesday.

[citronut]

does it have the brown double sized ECU protection relay, as i had this on a petrol pug 206 a few years back,

my DIS-LEXIA could not see the ECU at all, this particular one the realy lived under the ECU on the O/S inner wing, and it had a chunk of its housing missing, so had filled with water

[addo]

Hi Malcolm, do you mean the relay with a single wire plug and one of those sliding clip plugs as well?

[wheeler]

The brown double injection relay is now incorporated into the under bonnet fuse box (BSM) on modern full multiplexed PSA cars so this has already been ruled out.
Did the van run before it was messed about with for the blowers fault ?
I think you need to get a wiring diagram & check all the supplies & earths to the engine ECU.

[addo]

Hi, the van allegedly started and ran normally before they tinkered up the blower feed.

I've the SEDRE diagrams, haven't specifically checked earths but there is nil sign of corrosion to wires.

[addo]

Think I've got to the "why" of this - the grounding pins on the ECU had overheated and lost their solder. The case had a 4V standing voltage!

Unhappy with an ECU replacement until I have more understanding of the root cause.

[wheeler]

Can't you just re solder them ?
If it was me I think I would run new earths to the ECU just by splicing into the original wires (but leave the originals in place too) & maybe even add an additional earth straight to the ECU casing to the body

[addo]

Yes, as it was a sublet job and everyone was in a rush, that was what eventuated. Curious - have you ever seen this fault?

The naughty blower relay was replaced with a 40A unit and beefy spade connectors.

[wheeler]

Never seen this problem before, was just thinking it may be a high resistance in the earth circuit & the solder may have been the weakest link.